Blackboard-eraser



(No Model) J HAGGERTY BLAOKBOARD FRASER.

Patented Nov. 14, 1893.

UNITED ST TES PATENT OFFICE.

JoI-I HAeeERTY, or BRADFORD, PENNSYLVANIA.

BLACKBOARD- ERAS ER.

SPECIFICATION forming part of Letters Patent No. 508,704, dated November14, 1893.

Application filed-February 25.18%. Serial No.463,664. (No model.

To all whom zit-may concern: 7

zen of the United States,residing at Brad ford, in the county of McKeanand State of Pennsylvania, have invented certain new and usefulImprovements in Blackboard-Erasers, of which the following isaspecification,reference being had to the accompanying drawings, inwhich Figure 1 represents a side elevation of my black-board eraser, andshows the erasing stripsinserted transversely to the body. Fig. 2represents a top view of the same and shows the ends of the erasingstrips projecting beyond the body. Fig. 3 represents a side elevation ofmy black-board eraser in which the erasing strips are insertedlengthwise of the body. Fig. 4. represents an end view of the form shownin Figs. 1 and 2, and Fig. 5 represents an end view of the form shown inFig. 3.

The object of my invention is to provide a black-board rubber that willreadily remove all traces of the chalk from the surface of the Iblack-board.

1 is the body formed with thelateral finger grooves 2 and end grooves 3which adapt it to be grasped and firmly held while in use. The eraser isalso formed with either the'trans verse grooves 4, or the longitudinalgrooves 5, indicated by a dottedline in- Fig. 3 which soft or fibrousmaterial, but I prefer to use felt, it being soft,-yet firm and inwearing retains its angular form.

It will be observed that in Fig. 2 the ends of the erasing strips 6,project beyond the edges of the body 1. It will also be observed thatthe bottom of the body curves upward at the ends and that the bottoms ofthe transverse grooves at the ends in Fig. 1 and also the bottoms of thelongitudinal grooves 5 in Figs. 3 and 5, are substantially parallel withthe under side of the body 1 at those points.

7 Theobject of thus'projecting theends of the Be it known that 1, JOHNHAGGERTY, a citi-,

erasing strips 6 and of so forming grooves is to so dispose the erasingstrips that no matter which st rip of my eraser is used, the blackboardwill be fully protected from being defaced by contact of the body 1.

In the use of a cloth as an eraser of chalk marks, the cloth does notfully erase, but spreads the chalk in a thin layer over the black-board,necessitating frequent washings of said board in order to clean it. Itis well known'that square edges of the eraser assist greatly in theoperation by scraping off the chalk. In the use of erasers with a plainflat surface, only that edge toward the direction in which the eraser ismoving acts effectively as an eraser, the tendency of the fiat surfacebeing to spread over the board, the chalk not removed by the said edge.But, in my eraser, a series of edges act on the chalk-marksand when inuse each edge acts as a scraper and the particles of chalk removed byeach,immediately leave the black-board and fall into the recessesbetween the strips from which they can be dislodged by a gentle knockwithout raising a dust, and the black-board is thus cleaned of chalkrapidly and effectively.

The erasing strips form angular ribs spaced apart on the face of thebody, and inasmuch as they wear evenly in a plane transverse to theirbody, there are always left the rectangular edges which give efficiencyto the article Muse. The end strips are formed with diverging sides andare thus made heavier and stronger than the intermediate strips.

Having thus described my invention, the following is what I claim as newand desire to secure by Letters Patent:

1. A black-board eraser provided with a series of rectangular pieces offelt or similar material formed with plane faces Whose ends projectbeyond the body of the eraser, as set forth.

2. A black-board eraser provided with a rubbing surface, consisting of aseries of transversely secured rectangular strips of feltor' similarmaterial having plane faces in combination with similarly formed endstrips of larger transverse sectionthan the main strips as set forth.

3. A black board eraser consisting of a grooved body, strips of felt orsimilar material secured in the grooves in said body, and 5. The hereindescribedblack-board eraser a facing of paper or similar protectivemateprovided with a body having fiat faces and rial secured to the bodyof the eraser between beveled ends, a series of rectangular strips se-15 said strips, as set forth. cured to said flat face and beveled endsand 5 i. The black-board eraser herein described having their rubbingsurfaces parallel with consisting of the body provided with grooves saidface and ends, all substantially as and cutlgt rigllilt angles to itsface, having beveled for the purpose set forth.

en in w ich are cut grooves at right angles A 1 to their faces andrectangular strips of felt or JOHN HAGGLRTY' 10 other material securedin all of said grooves Witnesses:

and having plane erasing faces parallel with AUSTIN '1. HERRICK, thefaces of the body, as set forth. BEN. R. HAGAR.

